Light-signal



C. S. SNAVELY.

LIGHT SIGNAL.

APPLICATION FILED NOV. I9, 1915.

1 ,329, 6 39 I Patented Feb. 3, 1920.

3 SHEETS-SHEET 2- I XVENgORI 4- C. S. SNAVELY.

LIGHT SIGNAL.

APPLICATION FILED rIov. I9, I9l5.

2 ,639; Patented Feb. 3,1920.

3 SHEETS-SHEET 3.

FIG. 10

UNITED STATES PATENT OFFICE.

CLARENCE S. SNAVELY, OF EDGEWOOD BOROUGH,'PENNSYLVANIA, ASSIGNOB TO THEUNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, ACORPORA TIONOF PENNSYLVANIA.

LIGHT-SIGNAL.

Specification of Letters Patent.

Patented Feb. 3, 1920.

Application filed November 19,1915. Serial No. 62,341. v

To all/whom it may concern:

Be'it known that I, CLARENCE S. SNAVELY,

a citizen of the United States, residing at yments in Light-Signals, ofwhich the following is a specification.

My invention relates to "the adjustment of incandescent electric lampsso that the filament of the lamp will occupy a predetermined positionwith relation to the lamp bulb. I

Incandescent lamps which have been adjusted in accordance with myinvention are particularly adapted for use in apparatus comprising alamp and an optical device such use reflector or a lens or bothforprojecting a beam of light from the lamp; such apparatus may, forexample, be a light signal for use in railway signaling. In apparatus ofthis type it is desirable to arm ploy what is known as concentratedfilament lamps; that is, lamps whose filaments are concentratedas'nearly as possible at a point. In order to obtain the highestefficiency, it is necessary that the filament belocated at a definitepoint with relation to the reflector or lens, this point usually beingthe focus. In the manufacture of these lamps, however, it has been founddifiicult to locatethe filament accurately in a predetermined positionwith relation to the bulb, so that this position varies with differentcommercial lamps,'henceeve'n if the bulbs are all mounted in the sameposition in the signal the filaments of the several lamps will vary inposition with respectto the reflector or lens. Y

My invention, therefore, provides for ad; ju'sting the parts of acommercial lamp so that the filament will occupy a redetermined positionwith. respect to t e lamp bulb? means can then be provided in the signalformounting the lamp so that the bulb occupies a predetermined .positionwith respect to the reflector or lens, this position being such that thefilament will occupy the desired posilion with relation to the opticaldevice or devices of. the signal-. When the lamp is replaced by anotherroperly ad ,vented certain new and useful Improvewith respect to theoptical device or de vices, ,so that no adjustment is required in thesignal itself. I

In the accompanying drawings, Figure 1 IS a view-showing one form ofapparatus for adjusting the" filament of a lamp with respect to the bulband embodying my in- 1 vention. Fig. 2 is a plan view of member 7 shownin Fig. 1. Fig.v 3 is a View showing.one type of standard adapted foruse with the apparatus shown in Fig. .1. Figs. 4 and 5 are views showingone form of pliers for bending the neck of the bulb of lamp L. Fig. 6 isa viewshowing one form of base for the lamp bulb. Fi s. 7 and 8 areviews showing one form 0 ap aratus embodying my invention for locatinthe lamp bulb with respect to a lens. ig. 9

..1s a view showing a modification of the ap' paratus shown in Figs. 7and 8. Fig. 10 is a" plan view showing a modification of the apparatusshown in Fig. 1. Fig. 11 is a view showing in vertical section the aparatus shown in Fig. 10. Figs. 12 an 13 are views, showingdiagrammaticall another modification of the. method em odying myinvention or locating the filament 1 gt a predetermined position withinthe lamp ulb. Similar reference characters refer to similar parts ineach of the several views.

With reference to Fig. 1 the letter A des- 35 ignatesfia base plate onwhich is fastened by screws 1 a C-shaped supportingframe 2.

Reference character K designates a clamp .for grasping the bulb 4 of anelectric into receive nuts 10. Pins 9 are adapted to justed lamp, thefilament of t e new lamp I will, of course, occup'y the proper positionenter slots 1.1 in plate 7, so that, when nuts 10 are drawn'up, theplate clamps the lamp bulb firmly against the u er member 5.

It, is apparent that clamp 'is very simple to manipulate- A simplecounter-clockwise twist allows lamp L to be removed from the clamp andconversely a clockwise twist clamps the lamp in place. The firmness of j25 portion" 55 flames 1m inge on the state.

the grip of the clamp can easily be adjusted by nuts 10. Qlamp K'ismounted onmemher 2 by means .of a st'ud'3 which extends upwardly fromthe center of member 5 5 through aliole in frame 2. A head 12 is fixedto the upper end of the stud by a pin 13, so that the clamp depends fromframe 2 and is free to turn about its vertical axis a'b. However, forpurposes which will to appear hereinafter, it is desirable to" limit theangular motion of clamp K to approximately a right angle. 'This maybedone by .any suitable. means-such, for instance, as

pegs 35 screwed into the upper member 5 of 15. clamp K approximately 90apart (only one of these pegs appears on the drawing) The pegs areadapted to engage a stud 36 secured in frame 2, so that the-motion ofclamp K is limited to the angle between pegs 35. p

- Reference character T designates a tele scope, one end of whichextends through a hole in frame 2' and rests in a circular openmg in aplate'14 screwed to the .vertical frame 2, and the other end of which ismounted-by adjusting screws-15 in the ring-shaped end of an arm 16riveted in frame 2. Reference character B denotes a blow pipe whosevertical tube 17 is adjusted to a sliding fit in a sleeve 18 extendingthrough the lower horizontal portion of member 2 and base A." The lowerend of tube 17 is adapted to receive gas and air from flexible tubes 26and 27. The upper end oftube 17 has a shoulder 19 over which fits ahollow pulley 20. A collar 21 engages the lower edge of shoulder 19 andis screwed top'uIley 20 so that the pulley is prevented from slippingoff the .top of the tube. Pulley 20 is pro-' yidid with a tubularextension 24 closed at ltsupperend. Two diametrically opposite arms22-*and 23 ranch out from extension 24 and terminate in tips 25. Themixture. of gas and air flowing through tube 17 forms into two jets,one'from each tip 25.

If the pulley is revolved by suitable means notshown, these jets are setinto rotation and, when ignited,.apply an ,even heat to '60 an objectinserted between them. Theblow pipe normally slides downward by gravityuntil collar 21 is seated on the upper flange of sleeve 18. When theblow pipe is raised" to the osition shown in the drawing, the neck ofbulb 4, so that the g ass is readily heated to a ductile The use of theapparatus as thus far described may be explained as follows. The

operator inserts a standard S into member 5 of clamp K as shown in Fig.3. He then adjusts the telescope until its cross hairs cover the balltip 30 of a stud extend-- downwardly from the center of stand S. Theoperator then removes the standard but leaves the telescope in the adjusted position. It may be noted that the telescope is now so directedthat its line of sight intersects the vertical axis w-b of clamp K at afixed distance below member 5 of the clamp. The operator then fastens alamp L in the clamp and proceeds to heat the neck of the lamp bulb byraisin the blow pipe tothe'position shown in the rawmg. After therapidlyrotating flame of the blow pipe has heated. the neckof the.

that the stem is forced to follow the moveroent of the plier tips. Theoperator turns clamp K until one of the pegs 35 engages stud 36, sightsthrough the telescope and brings the filament into the intersection ofthe cross hairs by proper manipulation of the pliers. Hethen turns clampK through an approximate right angle, z. e., until the other peg 35engages stud 36,-and repeats the operation. 3 In the above-describedmanner the operator has brought the filament into the same positionrelative to member 5 of clamp K as the ball tip 30 of the standard Soccupied when it was inserted into the clamp K for adjustmentof theposition of the telescope. This is also true of the filament of everylamp subsequently adjusted. It follows that the filaments of all thelamps adjusted in i i this manner occupy the same pre-determinedposition with respect to the bulb surface.

* I The lamp bulbs are next provided with a base, for example, such asIhave shown in Fig. 6. ,Reference character 40 designates a shell ofinsulating material having a central prong 41, the tip of which isinserted into the hollow stem 32. The lead-in wires which pass throughstem 32 are connected to metallic-studs ,43 whose heads are fastoned inshell 40 and whose shanks extend outwardly from the shell as shown.

cement 45. v a

In Figs. 7 and 8 Ihave shown the lam'p placed intb proper position withrespect to a pair of Fresnel lenses. Reference characxters 46 denote apair ofsprings attached by means of screws 48 and terminal posts 4! to arigid supporting member 47 of insulating material. Member 47. and theFresnel lenses are mounted in a casing which I have not shown on thedrawing, sothat they are The baseis fixed to the lamp bulbby a suit-ablecircular recesses 50.

' Y sulating material is riveted at. its ends-to springs 46 and isprovided at its middle with a stud 52 whereby the springs may beconveniently bent. The lamp is inserted'by the simple process of placingthe upper end of the bulb into a corresponding recess in the Fresnellens, pulling the springs backmeanthat for dissimilar ward bystud 52 andslipping the studs 43 into the recesses 50. Thepressure of springs 46notonly holds the lamp in place with respect to the lens,'but alsocauses a firm contact between'springs 46 and studs 43 so that thecircuit is completed from one terminal post through the lamp filament tothe other terminal post.

As indicated in Fig. 7 the lamp filament is at the focal point of theFresnel lens combination. This is made possible withoutadjusting thelamp relative to the lenses because, as described hereinbefore, thefilament is at a definite position in the lamp bulb, which position issuch that the filament occupies the focal point as shown when the lampbulb is clamped in position. Naturally the filament of any lam bulbsimilar in size and shape and similar adjusted will occupy the focalpoint w en substituted for the first lamp. L

Sometimes the focal distance of the lens is so long that the lamp bulbwould have to be excessively large in order to be located by a recess inthe lens proper. In that case I provide a casting comprising a ring 55for receiving one end of the lamp bulb as shown in Fig. 9. Three spiderarms 56lead from ring 55 to another ring 57 which is adapted to receivethe lens. In this manner the lens and the lamp are both fixed with resect to the casting, so that the lamp and t e lens are also fixed withrespect to each other. The distance between rings 55 and 57 is such thatthe filament of the lamp occupies the focal point of the lens, or anyother desired pointwith respect thereto, when the lamp is placed intothe position shown on the drawmg. a

It should be noted here that it is not-essential that all the signallamps have bulbs of exactly equal size and shape, provided that theclamp which secures the lam in the signal is similar to the clamp whicsecures the lamp in the adjusting stand. By this I amp bulbs the surfacea of ring 55 (Fig. 9) against which the bulb rests in the signal must beexactly the same as the surface I) of member 6 of clam K (Fig. 1)against which the bulb is clamped 'while the filament is being ad usted.For, no matter what the size or shapc of the bulb, the filament after adustmen 1s at a definite predetermined position wit respect to thesurface b of clamp K, and it will be 'in a de at the same relativeposition to surface a of ring 55- whenthe lamp is clamped to the ring.Of course, care must be taken that the ring 55as shown on the drawing.

Instead of a telescope other optical de vices ma be used for locatingthe filament h nite position with respect to the lamp bulb. In Figs.wand 11 I have shown, for example, a clamp K (similar to the clamp Kshown in Fig. 1) provided with two so-called sights T and T of thefollowing construction. As shown in Fig. 11, sight T comprises avertical supporting member 60 fastened at its upper end to clamp K byscrew 61 and bent at'right angles at its lower end to support aninclosmg casing 62. Inside casing 62 is'a mirror 63.

at an angle of 45 degrees to the vertical and V I a lens 64 adapted toreceive light entering the casing through a hole in member 60.

' The upper face of the'casing 62 comprises a plate of ground glass 65.As .shown in Fig. 11 rays of light from lampfilament 31 pass' throughlens 64, are reflected from mirror 63, and are focusedon the filament(as shown in dotted lines in Fig.

10). Sight T is of similar construction to round lass screen 65, wherethey form an image 0 the sight T this image is at right angles to theimage in sight T The center of each sight T and T is determined b crosshairs on the ground glass 65 and t e sightsfare' so adjusted before theyare fixed to clamp K that they definitely locate a point on the verticalaxis of clamp K at a predetermined distance below its upper member 5'.In the use of this a paratus, the operator fastens the lamp bulli 4 inthe clamp similarl as described for Fig. 1 and heats the nec of the lampby suitable means as hereinbefore described. He' then inserts the jawsof the pliers shown in Figs. 4 and 5 into the stem 32 and bends the neckof the lamp bulb until indicated by the positioif of the images of thefilament with respect to the cross hairs of both sights T and T, asshown inFig. 10.' Since thc'operator is able ,to watch both sights T andT sin'mltaneously, this method of adjustment is more expedient than themethod described in connect-ion with-Fig. 1.

Still another way of securing an accurate the filament is in the desiredposition as is adjustment of the lamp filament with respect to the lampbulb is shown in Figs. 12 and 13. In this method I make use of theso-called-refiex image of a lamp filament in a. spherical or elliptical.lamp bulb. The.

spherical lamp bulb acts as a reflector of the filament within the bulband produces an image of the filament as far, to one side of the centerof the bulb as the filament isdisplaced from the opposite side of thecenter, as I have indicated diagrammatically in Fig. 12. The refleximage ofthe filament is barely visible when the filament is coldbut isdistinctly noticeable when the filament is heated to a dull red. For useof the re flex image of the filament for adjusting the filament withrespect to the bulb the operator connects the lead-in wires of thefilament to a source of potential of a suflicient voltage to send enoughcurrent through the filament to cause it to come to a dull red glow. Hethen applies heat toathe neck of the lamp bulb, inserts the jaws of thepliers into the hereinbefore described, and

stem 32, as bends the neck of the bulb until the filament occupies thedesired position with res ect to its reflex image. If for instance, itis esired to locate the filament centrally in the-lamp bulb, theoperator adjusts the filament until the reflex image coincides inposition with the filament, as shown in Fig. 13. It is apparent thatthis is a very expedient method for securing adjustment of the filamentwith the reflex image.

respect to the bulb and is of special advan tage where it is desired tolocate the filament in the center of the. lamp bulb, although it ispossible to secure an accurate location of the filament above or. belowthe center of the bulb by adjusting the filament so that the image is ata given Although I have herein shown and described only a few forms ofapparatus em-i bodying my invention, only a few methods embodying tionand modifications may be made therein my invenwithin the scope of theappended claims without departing from the spirit and scope distanceabove or below;

and have explained it is understood that various changes the bulb, andlocating the filament 1 optical means at 'a predetermined posi- I thedesired position of the filament 1,329,,csa

which the filament is, attached, and then moving the filament to suchpredetermined position. i

3. The method of adjusting commercial incandescent lamps which consistsin determining by optical means the desired position of the filamentwith'respect to the bulb surface, heating to a plastic state the portionof the bulb to which the filament is attached,

and then moving the filament to such predetermined position.

4. The method of adjusting commercial incandescent electric lamps whichconsists in; applying heat to render the filament movable with respectto the bulb, and moving the filament'to a predetermined" position withrespect to the bulb surface.

5. The method of adjusting incandescent electric lamps, which consistsin heating to a plastic state the portion of the lamp 'bulb to which isattached the stem carrying the filament, whereby the stem may be movedwith respect to the bulb, and moving the stem until the filamentoccupies a predetermined position with respect to the bulb.

6. Apparatus for adjusting commercial incandescent electric lamps,comprising means for rendering the lamp filament movable with respe'cttothe lamp bulb, and means for determining when the filament occupies apredetermined position with respect to the surface of the bulb.

7. In combination, a base member, means for mounting a lamp bulb thereonin a given osition, means for applying heat to said ulb to render thesame plastic whereby the filament may be moved with respect to the bulb,and optical means carried by said base member for determining whenthefilam'ent occuples a predetermined position with respect to said basemember.

8. In combination, a base member, meansfor mounting a commercialincandescent electric' lamp thereon so that the bulb surface'occup'iesa. predetermined osition with respect to said member, means or renderingplastic the portion of the bulb to which the lament is attached wherebythe filament may be moved with respect to the bulb, and

optical means for determining when the filament occupies a predeterminedposition'with respect to said base member. y

9. In combination, a base member, optical means for determining a. fixedint with relation -to said member, means or holding a lamp bulb to saidmember in a -predeter-.

mined position with relation 13088.1(1 point, and means for heating to aplastic state the portion of said bulb to which the filament is attachedwhereby the filament man be moved to said point. e

10. In combination, means for holding an incandescent lamp bulb, and arotary gas jet for heating to a plastic state the portion of said bulbtowhich thefilament isfiatof the bulb surface occu position with respectto said lens. a '13; The process of locating the filament of anincandescent lamp with res ect to the 'e tached, whereby the filamentmay be ad-' justed with respect to the bulb.

11. In combination, optical means for projecting a beam of light, anincandescent amp having the filament accurately located at a given pointwith respect to a portion of the surface of the bulb, and meansfor'mounting said electric lamp so that the said 7 portion of the bulbsurface occupies a predetermined position with respect to the saidoptical means.

P 12. In combination, I a. lens, an incandescent lamp having thefilament accurately located at a given point with respect to a portionof the bulb surface, and means for mounting said lamp so that the saidportion bulb surface which comprises eating the .end of the bulb whichsupports the filament; T determining b -o tical means the plro cationfor sai I ament, bending t 6 brought into' said mg t pics apredetermined erlo eated I surface of the bulb so that said filament is'25 proper location, and coole heated "surface; a a I 14. In combinationmeans for holding an incandescent lamp bulb, a rotary jet for heating toa plastic state .the portion of said bulb to which the filament isattached where- .by, the filament may be moved with respect tothebu1'b,- and optical means for determining when the filament occupiesa predetermined osition with respect to the bulb.

15. he method of locating the filament of an incandescent lampaccurately with respect to an optical device, which consists inaccurately locating the filament with respect to a portion of thebulb'surface and accurately locating "said portion ofthe bulb sur'-.

